/*
 *「open()」の関数を修正しました。
 *	端末ではデフォルトのカメラを開かれます。
 * 2013/12/23
 * */
package com.komeri.komeriapl;

import static com.komeri.komeriapl.Constants.*;

import java.io.IOException;
import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.PixelFormat;
import android.graphics.Point;
import android.graphics.Rect;
import android.hardware.Camera;
import android.hardware.Camera.CameraInfo;
import android.os.Build;
import android.os.Handler;
import android.util.Log;
import android.view.SurfaceHolder;

/**
 * This object wraps the Camera service object and expects to be the only one talking to it. The
 * implementation encapsulates the steps needed to take preview-sized images, which are used for
 * both preview and decoding.
 * @author Liu Mingjia
 **/
public final class CameraManager {

  private static final int MIN_FRAME_WIDTH = 240;
  private static int MAX_FRAME_WIDTH;

  private static CameraManager cameraManager;

  /**
   * Later we can use Build.VERSION.SDK_INT
   * */
  static final int SDK_INT; 
  static {
    int sdkInt;
    try {
    	
      sdkInt = Integer.parseInt(Build.VERSION.SDK);
      
    } catch (NumberFormatException nfe) {
    	
      // Just to be safe
      sdkInt = 10000;
    }
    SDK_INT = sdkInt;
  }

  private final Context context;
  private final CameraConfigurationManager configManager;
  private Camera camera;
  private Rect framingRect;
  private Rect framingRectInPreview;
  private boolean initialized;
  private boolean previewing;
  private final boolean useOneShotPreviewCallback;
  private BarCodeType barCodeType;

  /**
   * Preview frames are delivered here, which we pass on to the registered handler. Make sure to
   * clear the handler so it will only receive one message.
   */
  private final PreviewCallback previewCallback;
  /** Autofocus callbacks arrive here, and are dispatched to the Handler which requested them. */
  private final AutoFocusCallback autoFocusCallback;

  /**
   * カメラ管理の初期化
   * */
  public static void init(Context context, BarCodeType type) {
	  
    if (cameraManager == null) {
    	
      cameraManager = new CameraManager(context);
    }
    
    //cameraManageはインスタンスが使いまわされるため、
    //バーコードスキャン、QRスキャンで使用時、値の一部を変更する
    cameraManager.barCodeType = type;
    
    //初期化時にクリアする
    //クリアしないと、以前のスキャン時の設定が残ってしまい、スキャン枠の大きさ、スキャン領域が不正になる
    cameraManager.framingRect = null;
    cameraManager.framingRectInPreview = null;
    
    //TODO:QRコードの枠の大きさは暫定
    //スキャンするバーコードによって、スキャン枠の大きさを変更する
    switch (cameraManager.barCodeType) {
		case BARCODE:
	  	  MAX_FRAME_WIDTH = 480;
	  	  break;
	  	  
	    case QRCODE:
	  	  MAX_FRAME_WIDTH = 450;
	  	  break;
	  	  
	    default:
	  	  MAX_FRAME_WIDTH = 480;
    }
  }

  /**
   * Gets the CameraManager singleton instance.
   *
   * @return A reference to the CameraManager singleton.
   */
  public static CameraManager get() {
	  
    return cameraManager;
  }

  /**
   * @param context
   * */
  private CameraManager(Context context) {

    this.context = context;
    
    this.configManager = new CameraConfigurationManager(context);

    useOneShotPreviewCallback = Integer.parseInt(Build.VERSION.SDK) > 3; 

    previewCallback = new PreviewCallback(configManager, useOneShotPreviewCallback);
    
    autoFocusCallback = new AutoFocusCallback();
  }

  /**
   * Opens the camera driver and initializes the hardware parameters.
   *
   * @param holder The surface object which the camera will draw preview frames into.
   * @throws IOException Indicates the camera driver failed to open.
   */
  @SuppressLint("NewApi")
public void openDriver(SurfaceHolder holder) throws IOException {
	  
      if (camera == null) {
 
          camera = Camera.open(getDefaultCameraId());
    
          if (camera == null) {
        	
    	      throw new IOException();
          }
         
          camera.setPreviewDisplay(holder);
          
          if (!initialized) {
        	 
              initialized = true;
             
              configManager.initFromCameraParameters(camera);
          }
          
          configManager.setDesiredCameraParameters(camera);
          
      }
  }

  @SuppressLint("NewApi")
  private int getDefaultCameraId(){
	  
      int defaultId = -1;
      int mNumberOfCameras = 0;
      // Find the total number of cameras available
      mNumberOfCameras = Camera.getNumberOfCameras();

      // Find the ID of the default camera
      CameraInfo cameraInfo = new CameraInfo();
      for (int i = 0; i < mNumberOfCameras; i++) {
          Camera.getCameraInfo(i, cameraInfo);
          if (cameraInfo.facing == CameraInfo.CAMERA_FACING_BACK) {
              defaultId = i;
          }
      }
      if (-1 == defaultId){
          if (mNumberOfCameras > 0) {
              defaultId = 0;
          }
      }
      Log.e("getDefaultCameraId", String.valueOf(defaultId));
      return defaultId;
  }
  
  /**
   * Closes the camera driver if still in use.
   */
  public void closeDriver() {
	  
    if (camera != null) {
    	
      camera.release();
      
      camera = null;
    }
  }

  /**
   * Asks the camera hardware to begin drawing preview frames to the screen.
   */
  public void startPreview() {
	  
    if (camera != null && !previewing) {
    	
      camera.startPreview();
      
      previewing = true;
    }
  }

  /**
   * Tells the camera to stop drawing preview frames.
   */
  public void stopPreview() {
	  
    if (camera != null && previewing) {
    	
        if (!useOneShotPreviewCallback) {
    	  
            camera.setPreviewCallback(null);
        }
      
        camera.stopPreview();
      
        previewCallback.setHandler(null, 0);
      
        autoFocusCallback.setHandler(null, 0);
      
        previewing = false;
    }
  }

  /**
   * A single preview frame will be returned to the handler supplied. The data will arrive as byte[]
   * in the message.obj field, with width and height encoded as message.arg1 and message.arg2,
   * respectively.
   *
   * @param handler The handler to send the message to.
   * @param message The what field of the message to be sent.
   */
  public void requestPreviewFrame(Handler handler, int message) {
	  
    if (camera != null && previewing) {
    	
        previewCallback.setHandler(handler, message);
      
        if (useOneShotPreviewCallback) {
    	  
            camera.setOneShotPreviewCallback(previewCallback);
        } else {
    	  
            camera.setPreviewCallback(previewCallback);
        }
    }
  }

  /**
   * Asks the camera hardware to perform an autofocus.
   *
   * @param handler The Handler to notify when the autofocus completes.
   * @param message The message to deliver.
   */
  public void requestAutoFocus(Handler handler, int message) {
	  
      if (camera != null && previewing) {
    	
          autoFocusCallback.setHandler(handler, message);
      
          camera.autoFocus(autoFocusCallback);
      }
  }

  /**
   * Calculates the framing rect which the UI should draw to show the user where to place the
   * barcode. This target helps with alignment as well as forces the user to hold the device
   * far enough away to ensure the image will be in focus.
   * 縮小した矩形を取得する
   * @return The rectangle to draw on screen in window coordinates.
   */
  public Rect getFramingRect() {
	  
    Point screenResolution = configManager.getScreenResolution();
    
    if (framingRect == null) {
    	
      if (camera == null) {
    	  
        return null;
      }
      
      int width = screenResolution.x * 3 / 4;
      
      if (width < MIN_FRAME_WIDTH) {
    	  
        width = MIN_FRAME_WIDTH;
        
      } else if (width > MAX_FRAME_WIDTH) {
    	  
        width = MAX_FRAME_WIDTH;
      }
      
      //TODO:QRコードの枠の大きさは暫定
      int height = 0;
      switch (cameraManager.barCodeType) {
      	case BARCODE:
      		height = width * 3 / 4;
      		break;
      		
      	case QRCODE:
      		height = width * 9 / 10;
      		break;
      		
      	default:
      		height = width * 3 / 4;
      }
      
      //わく距離
      int leftOffset = (screenResolution.x - width) / 2;
      int topOffset = (screenResolution.y - height) / 2;
      
      //矩形を創建する
      framingRect = new Rect(leftOffset, topOffset, leftOffset + width, topOffset + height);
    }
    return framingRect;
  }

  /**
   * カメラとスクリーンの解像度により最適のズーム比を調整する
   * @return Rect
   */
  public Rect getFramingRectInPreview() {
	  
    if (framingRectInPreview == null) {
    	
        Rect rect = new Rect(getFramingRect());
      
        Point cameraResolution = configManager.getCameraResolution();
        Point screenResolution = configManager.getScreenResolution();

        rect.left = rect.left * cameraResolution.y / screenResolution.x;
        rect.right = rect.right * cameraResolution.y / screenResolution.x;
        rect.top = rect.top * cameraResolution.x / screenResolution.y;
        rect.bottom = rect.bottom * cameraResolution.x / screenResolution.y;
        framingRectInPreview = rect;
    }
    return framingRectInPreview;
  }

  /**
   * A factory method to build the appropriate LuminanceSource object based on the format
   * of the preview buffers, as described by Camera.Parameters.
   *
   * @param data A preview frame.
   * @param width The width of the image.
   * @param height The height of the image.
   * @return A PlanarYUVLuminanceSource instance.
   */
  public PlanarYUVLuminanceSource buildLuminanceSource(byte[] data, int width, int height) {
	  
      Rect rect = getFramingRectInPreview();
      
      int previewFormat = configManager.getPreviewFormat();
      
      String previewFormatString = configManager.getPreviewFormatString();
      
      switch (previewFormat) {
      
      	  // This is the standard Android format which all devices are REQUIRED to support.
      	  // In theory, it's the only one we should ever care about.
          case PixelFormat.YCbCr_420_SP:
          // This format has never been seen in the wild, but is compatible as we only care
          // about the Y channel, so allow it.
          case PixelFormat.YCbCr_422_SP:
        	  
              return new PlanarYUVLuminanceSource(data, width, height, rect.left, rect.top,
        			  rect.width(), rect.height());
          default:
        	  // The Samsung Moment incorrectly uses this variant instead of the 'sp' version.
        	  // Fortunately, it too has all the Y data up front, so we can read it.
        	  if ("yuv420p".equals(previewFormatString)) {
        		  
        	      return new PlanarYUVLuminanceSource(data, width, height, rect.left, rect.top,
        		          rect.width(), rect.height());
        }
    }
    throw new IllegalArgumentException("Unsupported picture format: " +
        previewFormat + '/' + previewFormatString);
  }

	public Context getContext() {
		return context;
	}
}
